Processed Meat Linked With Type 2 and Heart Disease

Red meat has long been suggested as a contributing factor to a variety of health problems, including Type 2 diabetes and heart disease. But a new analysis from the Harvard School of Public Health indicates that it may be processed meats specifically, rather than red meats per se, that are associated with a higher risk of these conditions.


Using a type of research known as meta-analysis (in which statistics from several studies are combined and examined), researchers looked at 1,218,380 people enrolled in 20 studies that included data about red meat consumption and the incidence of heart disease and diabetes. Unprocessed red meat was defined as any unprocessed meat from beef, lamb, or pork, but not poultry. Processed meat was defined as meat that had been preserved by smoking, curing, salting, or with chemical preservatives. Meats falling into the processed category included bacon, hot dogs, luncheon meats, salami, and sausages.

The data showed that, on average, eating at least one serving a day of processed meat was linked with a 19% greater risk of developing Type 2 diabetes and a 42% greater risk of developing heart disease. The consumption of unprocessed red meats was not associated with the development of these conditions.

Processed meats contain roughly the same amount of saturated fat and cholesterol as unprocessed meats but have four times as much sodium and 50% more nitrate preservatives, on average. In animal experiments, nitrates have been shown to reduce glucose tolerance and promote hardening of arteries, potentially increasing the risk of diabetes and heart disease; a high sodium intake is known to contribute to high blood pressure, which is also a risk factor for heart disease. The researchers suggest that further studies are needed to determine which characteristics of meats are most relevant to health outcomes.

According to lead researcher Renata Micha, RD, PhD, “To lower risk of heart attacks and diabetes, people should consider which types of meats they are eating. Processed meats such as bacon, salami, sausages, hot dogs, and processed deli meats may be the most important to avoid.” In an interview with heartwire, she noted that people “shouldn’t use these findings to eat as much unprocessed red meat as they like,” particularly since both processed and unprocessed meats have been associated with a higher risk of some cancers.

To learn more, read the article “Eating Processed Meats, but Not Unprocessed Red Meats, May Raise Risk of Heart Disease and Diabetes, Study Finds” or see the study’s abstract in Circulation.

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  • linda

    Actually, I’ve found that any form of meat or poultry raises my blood glucose levels. A primarily vegan diet with some fish and dairy works best for me.

  • Alex Rounds

    So actually avoiding nitrates and nitrites might be the solution. If I prepare my own bacon by smoking it and not adding the salt and nitrates, do I have the same risk? (I really like lean, heavily smoked bacon!)

    The same goes for making my own sausage. Who needs those nasty nitrates?

    The metastudy doesn’t discuss enough detail to draw good conclusions, I think.

  • zac

    The preservative in the processed of cold meats used [nitrates]is to preventing bacterial and give the pink red color. Hotdogs,ham,pepperoni,salami,corned beef.Now how harmful these substances are for humans is not well known.The sodium nitrates reacts with stomach
    acid and other chemicals in the stomach to produce nitrosamines which have been shown to cause cancer in animals when consumed in large quantities.I was in the process of meat products before in a meat factory and some meat products do contain large amounts of fat and little meat as well.[hot dogs like products beef pork sausages].Such substances do have side affects if taken in excss: such as poisoning,reproductive damage,and possible cancer.

  • acampbell

    Just wanted to add that even uncured processed meats (those that say “no nitrite or nitrate added”) may still form nitrites/nitrates during processing, especially if they’ve been processed with celery juice, which naturally contains a high level of nitrate. Cook’s Illustrated magazine sent samples of three brands of uncured bacon to a lab and all three brands had nitrite levels higher than the cured versions. So, it’s best to limit your intake of all processed meats and, to be on the safe side, consume a source of vitamin C when you eat processed meats. Vitamin C can inhibit the formation of nitrosamines, which are potentially carcinogenic.